Considering UE4 and Unity both support OpenGL, yes, a lot if not the majority of games.
WebGL and OpenGL ES are pretty much OpenGL. Formally they are different standards, but they are based all in OpenGL: if you know one, you know the others pretty well, which is what is important for developers as you agree in the second paragraph.
Once again, that's support not implementation. Developers could use OpenGL in Unreal. They could, but they haven't in general. Vulkan is the default, and is the more common choice.
If it were true that lots of games were picking OpenGL, why is it so hard to make a long list of them? It's easy to make such a list for vulkan.
WebGL and OpenGL ES are pretty much OpenGL. Formally they are different standards, but they are based all in OpenGL: if you know one, you know the others pretty well, which is what is important for developers as you agree in the second paragraph.